Each time there are more rains than the drainage system can take, there can be floods. Sometimes, there is heavy rain for a very short period that result in floods. In other times, there may be light rain for many days and weeks and can also result in floods. Rivers can overflow their banks to cause flooding.
In terms of lives lost and property damaged, floods are just behind tornadoes as the top natural disaster. In the United States, flood damages totaled $8.41 billion in 2011. There were 113 flood-related deaths. Floods can affect any area to some degree; wherever rain falls, flooding can occur.Jun 26, 2017
There are two main types of riverine flooding:Overbank flooding occurs when water rises overflows over the edges of a river or stream. ... Flash flooding is characterized by an intense, high velocity torrent of water that occurs in an existing river channel with little to no notice.
Control of Floods. Some methods of flood control have been practiced since ancient times. These methods include planting vegetation to retain extra water, terracing hillsides to slow flow downhill, and the construction of floodways (man-made channels to divert floodwater).